The strength of the aortic media and its role in the propagation of aortic dissection

Carson, Michael W.; Roach, Margot R.

doi:10.1016/0021-9290(90)90050-d

Cited by 69 publications

(33 citation statements)

References 17 publications

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“…While dissections of arterial tissues have been investigated in detail in previous works, 5,42,52,58 the failure mechanisms of plaque fissuring are unclear. Within this work we assumed a Rankine failure criterion, in which the occurring maximum principal stress was compared with the tissue-specific stress limit.…”

Section: Predicted Resultsmentioning

confidence: 99%

Modeling Plaque Fissuring and Dissection during Balloon Angioplasty Intervention

Gasser

Holzapfel

2007

Ann Biomed Eng

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Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage.

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Section: Predicted Resultsmentioning

confidence: 99%

Modeling Plaque Fissuring and Dissection during Balloon Angioplasty Intervention

Gasser

Holzapfel

2007

Ann Biomed Eng

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“…For example, it has been reported that a pressure as high as 600 mmHg is required to tear the media, that is, to cause dissection by infusing physiological saline into the media. 16) Much of the structure that confers the medial strength remains unknown, but it is believed to be derived from the interconnection of the components of the lamellar units. First, let us focus on the most important components, elastic fibers and smooth muscle cells.…”

Section: Ultrastructure Of the Normal Aortic Mediamentioning

confidence: 99%

Pathogenesis of Aortic Dissection: Elastic Fiber Abnormalities and Aortic Medial Weakness

Nakashima

2010

Annals of Vascular Diseases

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A lthough aortic dissection was previously a disease with an extremely poor prognosis, recent advances in diagnostic imaging and therapeutic modalities may improve its prognosis.1, 2) However, much of its etiology and pathogenesis remains unknown. In addition, new pathological variants of aortic dissection, such as intramural hematoma (IMH) and penetrating atherosclerotic ulcer, and related diseases have been identified, raising a new problem. Against this background, this paper revisits the basic pathology of aortic dissection, and discusses the structural abnormalities of the aortic media and mechanism of aortic dissection, as extrapolated from them. Medial Weakness: A Pathological Problem with Aortic DissectionAortic dissection used to be clearly defined as a pathological condition characterized by the presence of an aortic intimal tear and medial dissection, that is, a condition in which blood flows from the entry site into the false lumen.3) However, advances in diagnostic imaging have resulted in the identification of aortic dissection with no entry tear or false lumen flow, and these variants were included in the category of aortic dissection.4) For the differentiation between the two types of aortic dissection, the former is referred to as classic or communicating aortic dissection, and the latter as IMH or non-communicating aortic dissection. In IMH, no entry tear or false lumen flow is observed, strongly suggesting that no intimal tear exists anatomically. However, the limitations of diagnostic imaging make it difficult to establish its presence or absence. Therefore, it is doubtful whether IMH should be treated as the same entity as classic aortic dissection. However, in some cases, IMH has a poor prognosis in that it progresses to classic aortic dissection, or ruptures. Thus, clinically, it is believed that it is not contradictory to treat IMH as a variant of aortic dissection. 5,6) In contrast, pathologically, since the diagnosis can be confirmed by autopsy, IMH is clearly defined as a dissection without an intimal tear. 7,8) However, at the same time, the important question of whether dissection with a tear (classic aortic dissection) and that without a tear (IMH) is the same disease arises. This is related to the long-standing debate over which occurs first, intimal tear or medial dissection, in the development of aortic dissection. The former is the hypothesis that a crack (intimal tear) first forms in the intima overlying a site of aortic medial weakness, followed by blood inflow from the lumen, resulting in medial dissection.9) This is a very natural way of thinking in terms of the direction of blood flow. However, from this viewpoint, it follows that no dissection occurs without an intimal tear, making it contradictory to include IMH in the category of aortic dissection. On the other hand, the latter is based on the fact that no intimal tears were identified in about 10% of autopsied patients with aortic dissection, leading to a hypothesis that bleeding from the medial vasa vasorum at a site o...

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“…Carson et al [8] measured the value of pressure to initiate a dissection in strips of porcine upper thoracic aortas, as well as curves of pressure against the volume of the false lumen. Taking a slab of tissue from the longitudinal direction of the aortas with three layers (intima, media and adventitia), and infusing a fluid at a constant flow rate into the media, they found that as the pressure increased to 77 kPa, a bleb formed, and the tear started to propagate, at which point the flow into the dissection was halted.…”

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confidence: 99%

Acoustic scattering in a waveguide with a height discontinuity bridged by a membrane: a tailored Galerkin approach

Lawrie

Afzal

2016

J Eng Math

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An arterial dissection is a longitudinal tear in the vessel wall, which can create a false lumen for blood flow and may propagate quickly, leading to death. We employ a computational model for a dissection using the extended finite element method with a cohesive traction-separation law for the tear faces. The arterial wall is described by the anisotropic hyperelastic Holzapfel-Gasser-Ogden material model that accounts for collagen fibres and ground matrix, while the evolution of damage is governed by a linear cohesive traction-separation law. We simulate propagation in both peeling and pressure-loading tests. For peeling tests, we consider strips and discs cut from the arterial wall. Propagation is found to occur preferentially along the material axes with the greatest stiffness, which are determined by the fibre orientation. In the case of pressure-driven propagation, we examine a cylindrical model, with an initial tear in the shape of an arc. Long and shallow dissections lead to buckling of the inner wall between the true lumen and the dissection. The various buckling configurations closely match those seen in clinical CT scans. Our results also indicate that a deeper tear is more likely to propagate.

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The strength of the aortic media and its role in the propagation of aortic dissection

Cited by 69 publications

References 17 publications

Modeling Plaque Fissuring and Dissection during Balloon Angioplasty Intervention

Modeling Plaque Fissuring and Dissection during Balloon Angioplasty Intervention

Pathogenesis of Aortic Dissection: Elastic Fiber Abnormalities and Aortic Medial Weakness

Acoustic scattering in a waveguide with a height discontinuity bridged by a membrane: a tailored Galerkin approach

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